How does jquery achieve cross-domain access? Connect to other people's interfaces

• The following example you can refer to the following

  <script>

  $.ajax ({

  Async:false,

  URL: ' http://www.mysite.com/demo.do ',//cross-domain URL

  Type: ' GET ',

  DataType: ' Jsonp ',

  JSONP: ' Jsoncallback ',//default callback

  Data:mydata,

  timeout:5000,

  Beforesend:function () {//jsonp mode This method is not triggered. The reason may be that datatype, if specified as Jsonp, is not an AJAX event.

  },

  Success:function (JSON) {//client jquery pre-defined callback function, after successfully acquiring JSON data on a cross-domain server, this callback function is executed dynamically

  if (json.actionerrors.length!=0) {

  alert (json.actionerrors);

  }

  Gendynamiccontent (Qsdata,type,json);

  },

  Complete:function (XMLHttpRequest, Textstatus) {

  $.unblockui ({fadeout:10});

  },

  Error:function (XHR) {

  Jsonp mode This method is not triggered

  Request Error Handling

  Alert ("Request error (Please check correlation network status.)");

  }

  });

  Attention:

  $.getjson ("http://www.mysite.com/demo.do?name1=" +value1+ "&callback=?",

  function (JSON) {

  if (JSON. property name = = value) {

  Execute code

  }

  });

  </script>

How does jquery achieve cross-domain access? Connect to an interface provided by someone else